A repentant alcoholic, Henri is promised to the young Yvonne, but he is in love with Gisèle, her sister and the fiancée of his friend Hubert. They all go on vacation, to the villa of Valentine Bourjeon, the mother of the two young girls. Henri and Gisèle begin an affair which, despite a thousand precautions, is quickly discovered. Hubert seems to be the only one not noticing anything. Mrs. Bourjeon will restore order in the sentimental life of her daughters.